Impact tool



N0. 6|3,3||. Patented Nov. I898.

J. B. RHODES.

IMPACT TOOL.

(Application filed May 28, 1897. Renewed Apr. 4, 1898.) (No Model.) 5Sheets-Sheet I.

29, 1897 Renewed Apr 4, 189

No. 6l3,3ll. I J. B. RHODES. cation filed I K Sy TOOL- i'fiifn'lfimlmulmmlimlmnmll '6 r gmmm gum gqggggggiiiiiiiiiiiiI H 40 jay 2. I H" QI 5 "II 1 ll 1} mm; Mull i i i i ZZZ Patented Nov. l, I898.

5 Sheets-Sheet 2.

J. B. RHODES.

IMPACT TOOL.

tion filed May 28, 1 897. Renewed Apr.

7 2 a 1 I I /V Wm .W M f 9 (Applica Patented Nov. l, I898. .1, B. mmmas.IMPACT TOOL.

(Application filed May 28, 1897, Renewed Apr. 4, 1898.)

(No Model.)

5 Sheets-Sheet 4.

No. 6|3 ,3ll'. Patented Nov. I, 1898.

J. B. RHODES.

IMPACT TOOL.

(Application filed May 28, 1897. Renewed Apr. 4, 1898.)

5o tive fluid to the piston-chamber.

UNITED STATES PATENT OFFICE.

JAY B. RHODES, OF CHICAGO, ILLINOIS, ASSIGNOR TO FREDERICK C. AUSTIN, OFSAME PLACE.

IMPACT-TOO L.

SPECIFICATION forming part of Letters Patent No. 613,311, dated November1, 1898.

Application filed May 28, 1897. Renewed April 4, 1898-Seria1IT0.-676,4'79. (No model.)

To ctZZ whom it may concern:

Be it known that I, JAY B. RHODES, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented a certain new and useful Improvement in Impact-Tools, of whichthe following is a specification.

My invention relates in general to rockdrills or other impact-toolsadapted for oper: ation by means of steam, compressed air, or othermotive fluid under pressure and having a piston-chamber inclosing apiston which carries the drill or other implement, and it relates inparticular to a construction of impact-tool in which the piston isreciprocated within its chamber by a valve mechanism op eratingindependently of its movement, and comprising to such end afluid-actuated reciprocatin g distribution-valve or piston-valve, as itmay be termed, which by its reciprocation properly distributes motivefluid to the piston-chamber for reciprocating the piston, and a fluidactuated reciprocating valve which by its reciprocation admits motivefluid alternately to the opposite ends of the piston-valve chamber, soas to reciprocate the piston-valve, and which is reciprocated to suchend by motive fluid admitted alternately to the opposite ends of itsvalve-chamber by the reciprocation of the piston-valve. Thisconstruction, embodying, as it does, a valve mechanism operatingindependent of the piston movement, has heretofore frequently provedunsatisfactory, because the piston has been subjected to a period ofadmission too short to cause its effective reciprocationthat is to say,the discharge of motive fluid has been alternated from one side of thepiston to the other so rapidly as to prevent the latter from moving withany degree of force in either direction. This result has been due to thefact that the motive fluid has been admitted by the piston-valve to thepiston-chamber and to the supplemental-valve chamber at the same timeand that the supplemental valve has therefore been reversed so quicklythat it has caused a premature reversal of the piston-valve and aconsequent premature termination of the period of admission of mo- Theobviation of this objectionable feature is a prominent object of myinvention.

Other objects of the invention are to allow motive fluid to bedistributed independently in the piston-chamber and in thevalve-chambers, to reduce to a minimum the size of the tool, to protectthe supplemental valve from external injury, to arrange for anintermittent twisting or rotating of the drill or other implementwithout at the same time reducing the eflective piston area, to arrangefor an effective cushioning of the piston at the ends of its stroke, toallow the piston and valves to be easily, conveniently, and rapidlyremoved from and replaced within their respective chambers, and toprovide certain novel features of construction and arrangement tendingtoincrease the efficiency of such tools and to reduce their cost ofmanufacture, maintenance, and operation.

In an impact-tool characterized by my invention motive fluid which isadmitted alternately to the opposite ends of both the pistonchamber andthe supplemental-valve chambervby the piston-valve is admitted to thepiston-chamber before it is admitted to the supplemental valve chamber,and as a preferred arrangement it is admitted to the supplemental-valvechamber only at a time when the piston-valve reaches one or the other ofthe ends of its stroke. By thus admitting motive fluid to thepiston-chamber before it is admitted to the supplemental-valve chamberthe piston is given opportunity to acquire m0- mentum enough to strikean efiective blow before the supplemental valve is actuated to reversethe direction of motion of the pistonvalve, and thereby terminate theperiod of admission, and by delaying the admission of motive fluid tothe supplemental-valve chamber until the piston-valve has reached theend of its stroke the piston-chamber is supplied with motive fluid forthe longest possible period of time before the piston-valve is thusreversed by an actuation of the supplemental valve. 1

In the accompanying drawings, Figure 1 is a side elevation of animpact-tool embodying m y invention, certain portions of the same beingshown in section. Fig. 2 isa front eleva tion of the cylinders whichprovide the pistonchamber and piston-valve chamber, respectively. Figs.3 and 4 are horizontal sections taken on lines oczcand :12'00,respectively,in Fig. 2. Fig. 5 is a vertical section taken centrallythrough said piston and piston-valve cylinders, showing the piston-valvein elevation. Fig. 6 is a vertical and central section of the middlelongitudinal portion of the piston-cylinder on a larger scale. Figs. 7and 8 are horizontal sections takenon lines y y and y 3 respectively, inFig. 6. Fig. 9 is a view illustrating, on an enlarged scale, thepistonvalve cylinder and the piston-valve in section and thesupplemental valve in elevation. Figs. 10, 11, and 12 are horizontalsections taken on lines .22, 2'5, and 5 .2 respectively, in Fig. 9. Fig.13 is a vertical section similar to that of Fig. 5, illustrating amodified arrangement of the piston and supplemental valves. Fig. 14 is avertical elevation of the same with the cylinder which provides thesupplemental-valve chamber removed therefrom. Fig. 15 is a bottom planview. of said cylinder.

I have shown in the drawings a drill 1, connected by a suitableconnection 2 with a piston-rod 3, which latter is reciprocated so as toeifect the desired drilling operation by means of a piston arrangementinclosed within a piston-chamber A, which is conveniently provided by apiston-cylinder A.

The drill 1 is desirably twisted or rotated between its successive blowsfor the purpose of presenting it in a different position for each blow.To such end either the piston arrangement inclosed within thepiston-chamber A for reciprocating such drill or the piston-rod 3,connecting the piston arrangement and the drill, could be constructed inany suitable manner and could be connected in any preferred manner withsome suitable device for imparting such intermittent rotation ortwisting motion to the drill. As a matter of further improvement,however, the piston arrangement comprises a couple of separatedpiston-heads B and B and a connecting-rod 5, which latter is attached atits ends to said piston-heads B and B and is arranged in engagement witha device whereby it is intermittently twisted or rotated automaticallyby its own reciprocation, and thereby operates to twist or rotate thedrill between the successive blows thereof. By thus arranging thetwisting or rotating device intermediate of a couple of separatedpiston-heads the entire area of the upper face of the upper piston-headis exposed to the motive fluid when the same is admitted to the upperend of the piston -chamber, and the drill therefore is driven downwardwith the greatest force possible, whereas if such device were situatedat the upper end of the piston-chamber and a rod or the like extendedupward from the upper piston-head the exposed area of the upper face ofsuch upper piston-head would be decreased by the cross-sectional area ofsuch rod.

The piston-heads B and B, the piston-rod 3, and the connecting-rod 5 canbe conveniently constructed and secured together by forming thepiston-rod 3, the lower pistonhead B, and the connecting-rod 5 integralwith one another and by then screwing the upper piston head B upon thesuitablythreaded upper end portion of the connecting-rod 5, as bestshown in Fig. 5, it being observed that said connecting-rod 5 should beof such length with reference to its length of stroke as to allow thepiston-heads to reciprocate on either side of the intermediate twistingor rotating device without interfering therewith. I

The device inclosed within the pistonchamber and adapted for engagingthe connecting-rod 5 for intermittently twisting or rotating the samecould be of any suitable construction; but as a preferred arrangementand matter of further improvement such device comprises a couple ofcollars 7 and 8, inclosing the connecting-rod 5 and provided,respectively, with oppositely-arranged cooperating ratchet-teeth 9,whereby when the teeth 9 are in engagement the collars are lockedagainst relative rotation in one direction, but are free to rotate inthe opposite direction.

The upper collar 7 is secured within the piston-chamber against rotarymotion and sliding movementlongitudinallyofsaid chamber and fits looselyover and is disconnected from the connecting-rod 5, so as to allow thelatter to work freely within it. The lower collar 8, on the contrary,fits loosely within the piston-chamber, so as to allow of its beingrotated therein and also so as to allow of its being slid longitudinallythereof into and out of engagement with the upper fixed collar 7, andalso it engages the connecting-rod 5 by means of a number ofinwardly-projecting tongues 10,with which it is provided, and acorresponding number of grooves ll,formed longitudinally in saidconnecting-rod 5 and adapted to receive the tongues 10, said grooves 11being so inclined that the connecting-rod 5 tends during its rise toturn the collar 8 in the direction against which it is locked when inengagement with the upper fixed collar 7 and to turn said collar 8 inthe opposite direction during its descent; also, the loose collar 8 hasa friction connection with the connecting-rod 5as, for instance, bymeans of a friction clasp ring 12, inclosing the connecting-rod andinclosed in turn within a suitable annular chamber formed inter nally insaid collar 8, whereby the latter is slid automatically into and out ofengagement with the upper fixed collar 7 by the rise and descent of theconnecting-rod 5, and it is provided with a stop adapted to limit itsdescent when it has been moved downward by the connecting-rodsufficiently to cause it to become disengaged from the upper fixedcollar 7. By such arrangement the lower loose collar 8 is slidautomatically upward and into engagement with the upper fixed collar 7by the initial rise of the connectingrod 5 and is held there againstrotation during the remaining portion of the upstrokeof saidconnecting-rod. thereby causing the latter, and consequently the drill,to turn or rotate, and by the initial descent of the connecting-rod saidcollar 8 is slid automatically out of engagement with the upper fixedcollar7 and is rotated thereby during the remaining portion of thedownstroke, thereby allowingthe connecting-rod,andconsequently thedrill, to descend without rotating.

The collar 7 could be secured against rotation within the piston-chamberand the loose collar 8 could be provided with a stop limiting itsdownward movement in any suitable manner. As illustrative ofarrangements for such purpose I have shown in Figs. 5 to 7, inclusive,both of said collars inclosed within a sleeve 13, the collar 7 beingsecured tightly therein against movement and the loose collar 8 beingfitted loosely therein and the said sleeve 13 being in turn fittedtightly within the bore of the piston-cylinder A and provided at itslower end with an inwardly-extending annular flange 14, which serves asa stop for limiting the downward movement of the loose collar 8.

In Fig. 13 I have shown the collar 7 itself secured tightly within thebore of the pistoncylinder A, being to such end embedded in an annularrecess formed in the latter, and have shown also a disk '15, inclosingthe connecting-rod 5 and secured within the bore of the piston-cylinderA, below the loose collar 8, for the purpose of limiting the downwardmovement of the latter.

I have chosen to claim the broader features of the previously-describeddrill-twisting arrangement and the specific construction illustrated inFigs. 5 to 8, inclusive, in the present application and to claim thespecific construction illustrated in Fig. 13 in another application,illustrating the same and filed contemporaneously with the presentapplication.

With reference to the relative arrangement of the fixed and loosecollars 7 and 8 it willbe observed that the positions of the same couldbe reversed-that is to say, the lower collar could be fixed orstationary within the piston-chamber and the upper collar could be loosetherein; but I prefer the arrangement illustrated, chiefly for thereason that in it the connecting-rod 5 is disengaged from all mechanismtending to hold it against rotation during its downstroke, and the drilltherefore can turn freely without breaking or injuring itself or otherparts of the device, as required by peculiarities or irregularities inthe hole being drilled, whereas if the position of said collars wasreversed said connecting-rod would be engaged for rotation during itsdownstroke, and the drill therefore could not rotate except inaccordance with the rotation imparted to it as a result of its descentwithout injury to itself or some other part of the device.

The valve mechanism, which operates independently of the piston andwhich causes a reciprocation of the latter by effecting a properdistribution of motive fluid to the piston-chamber A, comprises areciprocating fluid-actuated cylindrical piston-valve D and 'areciprocating fluid-actuated cylindrical supplemental valve E, inclosed,respectively, in suitable valve-chambers D and E. The piston-valvedistributes motive-fluid to the piston-chamber A by-means of inlet-ports17 and 17 ,extending,respectively,from its valvechamber D to theopposite ends of the pistonchamber A and terminating in its valve-seat 18, and an exhaust-port 19, extending from its valve-chamber D to asuitable exhaust-outlet 20 and likewise terminating in its valveseat 18,Fig. 4, while the supplemental valve E distributes motive fluid to thepiston-valve chamber D, so as to reciprocate the pistonvalve D and isreciprocated in turn by motive fluid distributed to its valve-chamber Eby the piston-valve D, such cooperation being effected by means ofsuitable ports connecting the two valve-chambers.

In carrying out my invention it is of course possible to vary withinwide limits the arrangement and construction of the pistonvalve, thesupplemental valve, and the valvechambers therefor. As illustrative ofsuch possibilities of variation I have shown two differentarrangements,which embody certain broader features in common, but whichvary as to details of construction. One of these arrangements isillustrated in Figs. 4: to 12, inclusive, and the other in Figs. 13 to15, inelusive, of the drawings. I have chosen to incorporate in thisapplication the claims for the broader features common to botharrangements and for specific construction illustrated in Figs. 4 to 12,inclusive, and toincorporate in another application, filedcontemporaneously herewith, the claims for the specific constructionillustrated in Figs. 13 to 16, inclusive.

Referring first to the construction illustrated in Figs. 4 to 12,inclusive, of the drawings, it will be observed that thesupplemental-valve chamber E is provided by an internal bore formedconcentrically in the piston-valve D and adapted to contain thesupplemental valve E and also that the pistonvalve chamber D is providedby a cylinder F and is connected with a supply-chamber 21, which latterforms a continuation of and receives motive fluid from a main inletport22. The piston-valve chamber D is connected with the supply-chamber 21by means of a couple of pairs of inlet supply-ports 23 24 and 23 2 1*,which are formed in the wall separating said chambers from one another.In order to properly distribute motive fluid within the piston-chamberby its reciproca tion, the piston-valve D is constructed with upper andlower cirei'unferentially-formed recesses 25 and 25 and an intermediatesimilar recess 26, separated from the recesses 25 and 25 by cylindricalheads 27 and 27, which said recesses 25, 25, and 26 are so arranged asto allow either the upper end of the pistonchamber to receive motivefluid from the upper supply-ports 23 and 24 by way of its upperinlet-port 17 and the upper piston-valve reeess 25 and the lower end ofthe piston-chamber to exhaust into the main exhaust-port 19 by way ofits lower inlet-port 17" and the intermediate piston-valve recess 26when the piston-valve is below a predetermined point in its stroke or toallow the lower end of the piston-chamber to receive motive fluid fromthe lower supply-ports 23 and 24 by way of its lower inlet-port 17 andthe lower pistonvalve recess 25 and the upper end of the piston-chamberto exhaust into the main exhaust-port 19 by way of its upper inlet-port17 and the intermediate piston-valve port 26 when the piston-valve D isabove a predetermined point in its stroke.

It will be observed that the period of admission of motive fluid intothe inlet-port 17 begins when the terminal opening of said port is firstput into communication with the piston-valve recess 25 by the passage ofthe upper edge of the cylindrical head 27 beyond the upper edge of saidterminal opening during the downstroke of the piston-valve and that suchperiod terminates when said terminal opening of the port 17 is finallyshut off from communication with the piston-valve recess 25 by thearrival of said upper edge of the head 27 opposite said upper edge ofthe terminal opening of the port 17 011 the return upstroke of thepiston-valve; also, that in a similar manner the period of admission ofmotive fluid into the lower piston-chamber inlet-port 17 begins when thelower edge of the valve-head 27 passes beyond the lower edge of theterminal opening of said port 17 on the upstroke of the valve andterminates when said lower valve-head edge arrives at said lower edge ofthe port-terminal on the downstroke of the valve. It will be furtherobserved that although said piston-valve D is free to move in itschamber D the motive fluid passing thus in its circumferential recessexerts an equal pressure in both directions on the sides of suchrecesses, and therefore fails to move the valve. The piston-,valve D isreciprocated in its chamber D, so as to thus distribute motive fluid tothe piston-chamber A by motive fluid which is first admitted to thesupplemental-valve chamber E and is then discharged into and exhaustedfrom the piston-valve chamber D alternately on opposite sides of thepistonvalve D, according as the supplemental valve E is at one or theother of the ends of its stroke. To such end the piston-valve D isconstructed with a couple of sets of radial ports 28 and 28, Fig. 11,extending, respectively, between its upper recess 25 and the upper endof the supplemental-valve chamber E and between its lower recess 25 andthe lower end of the supplemental-valve chamber E, whereby motive fluidcan be admitted either to the upper or the lower end of thelatter,according as the recess 25 is in communication with the ports 23and 24 or the recess 25 is in communication with the ports 23 and 24.Said piston-valve D is also constructed with an intermediate set ofradial ports 29, Fig. 12, extending between its intermediate recess 26and the longitudinal middle of the supplemental-valve chamber E, wherebymotive fluid can exhaust from the middle of said chamber into theintermediate recess 26 and thence into the main exhaust-port 19, and isalso constructed with a couple of longitudinally-arranged ports 30 and30, extending, respectively, from one end of its ends to the end of thesupplemental-valve chamber E farthest removed therefrom, and having sideopenings 32 and 32, respectively, opening into said chamber E, by whicharrangement motive fluid admitted to one or the other of the ends of thesupplementahvalve chamber can be admitted to the piston-valve chamber tothe side of the piston-valve remote from such end of thesupplemental-valve chamber, and by which arrangement also motive fluidin the piston-valve chambercan be exhausted therefrom into thesupplemental-valve chamber sufficiently near the longitudinal middleportion thereof to allow it to pass into the intermediate recess 26.

The supplemental valve E is provided with a couple of circumferentialrecesses 33 and 33, formed by cylindrical valve-heads 35 and 36 and 35and 36, respectively, whereby m0- tive fluid can pass from the radialports 28 into the side opening 32 of the longitudinal port 30 when saidvalve is at the lower end of its stroke, Fig. 9, and from the radialports 28 into the side opening 32 of the port 30 when the valve is atthe upper end of its stroke, and is provided also with a longintermediate recess 34, formed by the valveheads 35 and 35, wherebymotive fluid can pass from the port 30 by way of its side opening 2 intothe radial ports 29 when the valve is at the lowerend of its stroke andfrom the port 3O by way of its side opening 32 into said radial ports 29when the valve is at the upper end of its stroke. By such arrangementwhen the supplemental Valve is at the lower end of its stroke, as shownin Fig. 9, motive fluid passes from the ports 23 and 24 into thepiston-valve chamber D below the piston-valve D by way of thepiston-Valve recess 25, radial ports 28, supplemental-Valve recess 33,side opening 32" of port 30, and port 30 and operates to move thepistonvalve upward, during which upward movement the upper end of thepiston-valve chamber exhausts into the main exhaust-port 19 by way ofthe longitudinal port 30, the side opening 32 thereof, the intermediatesupp1emental-valve recess 34, the radial ports 29, and the intermediatepiston-valve recess 26, and when the supplemental valve is at the upperend of its stroke motive fluid passes from'the ports 23 and 24 into thepistonvalve chamber D above the piston-valve by way of the piston-valverecess 25, radial ports 28 thereof, supplemental-valve recess 33, sideopening 32 of port 30, and port 30, and operates to move the pistondownward, during which downward movement motive fluid escapes from thelower end of the piston-valve chamber into the main exhaustport 19 byway of longitudinal port 30, side opening 32 thereof, the intermediatesupplemental-valve recess 34, radial ports 29, and the intermediatepiston-valve recess 26, it being observed that the motive fluid passingthus in the recesses of the supplemental valve exerts an equal pressurein both directions on said valve and so does not operate to move thesame.

The supplemental valve E is reciprocated by motive fluid, which isadmitted to and exhausted from the opposite ends of its chamber inalternation by the reciprocation of the piston-valve. To such end thepiston-valve is provided near its ends with circumferential recesses 37and 37, formed between cylindrical heads 39 39 and 39339 respectively,and also with radial ports 38 and 38, Fig. 10, which latter extend,respectively, between the upper recess 37 and the upper end of thesupplemental-valve chamber E and between the lower recess 37 and thelower end of said valve-chamber E. By such arrangement when thepiston-valve has descended suffioiently to bring the recess 37 intocommunication with the supply-port 24 motive fluid will be admitted tothe upper end of the supplemental-valve chamber E and will operate todrive the supplemental valve E downward, and when the piston-valve hasdescended sufflciently to bring the recess 37 into communication withthe supply-port 24 motive fluid will be admitted to the lower end of thesupplemental-valve chamber E and will operate to drive the supplementalvalve upward. The recesses 37 and 37 a could be so situated upon thepiston-valve D as to allow motive fluid to enter .one or the other ofthe ends of the supplemental valve chamber, so as to actuate thesupplemental-valve and thereby cause a reversal of the piston-valve atany desired time after motive fluid has begun to enter the correspondingend of the pistonchamber, it being observed that by thus delaying theentrance of motive fluid to the supplemental valve chamber until a timeafter it has begun to enter the piston-chamber the danger of causing apremature termination of the period of admission to the latter by a toosudden reversal of the pistonvalve is avoided. As a preferredarrangement, however, said recesses 37 and 37 are so situated as todelay such entrance of motive fluid to the supplemental-valve chamberuntil a time when the piston-valve has reached substantially one or theother of the ends of its stroke, as shown in Fig. 9, by whicharrangement is procured the longest possible period of admission ofmotive fluid to the piston-chamber.

As a matter of further improvement in the arrangement for reciprocatingthe supplemental valve, the longitudinal piston-valve ports 30 and 30are extended beyond their side openings 32 and 32% and are provided withend openings 31 and 31 respectively, which latter are so situated thatduring the descent of the supplemental valve E the end opening 31 isuncovered by the supplementalvalve head 36 at a time before the sideopening 32 is uncovered by the corresponding valve-head 35, andduringthe rise of the supplemental valve the end opening 31 is uncovered by the supplemental-valve head 36 at a time before the sideopening 32 is uncovered by the corresponding v alve-head 35. By sucharrangement the motive fluid admitted primarily to one or the other ofthe ends of the supplemental-valve chamber for the purpose of actuatingthe supplemental valve is subsequently discharged by way of one or theother of the ports 30 and 30 into the opposite end of the piston-valvechamber at a time immediately preceding the arrival of the piston-valveat one or the other of the ends of its stroke, and thereby operates tocushion said valve against shock at the ends of its strokes and also toinsure its quick reversal.

As an arrangement for properly exhausting the supplemental-valve chamberduring the movement of the supplemental valve, the piston-valve D isprovided with longitudinallyformed exhaust-ports 40 and 40 having outerend openings 41 and 41 and inner end openings 42 and 42, respectively,whereby motive fluid can pass from one or the other of the ends of thesupplemental-valve chamber into the intermediate recess 34 of saidvalve, as required by the movement of the valve. The outer ends 41 and41 of said exhaust-ports 40 and 40 are desirably so situated as to beclosed by one or the other of the valve-heads 36 and 36 at a timeshortly before the arrival of the supplemental valve at the ends of itsstroke, by which arrangement the escape of motive fluid during exhaustis cut off by the supplemental valve at such times, and the remainingmotive fluid is compressed, so as to form a cushion adapted to preventshock to said valve at the ends of its stroke. The result of such valvearrangement is that when the pistonvalve descends to the lower end ofits stroke, as shown in Fig. 9, motive fluid is admitted to the upperend of the supplemental-valve chamber and the supplemental valvedescends, which descent of the supplemetal valve operates to admitmotive fluid to the lower end of the piston-valve chamber and causes thepiston-valve to rise, and when the piston-valve arrives at the upper endof its stroke motive fluid is admitted to the lower end of thesupplemental-valve chamber and the supplemental valve rises, which riseof the supplemetal valve operates to admit motive fluid to the upper endof the piston-valve chamber and causes the piston-valve to descend, andso on, as before. This continuous and independent operation of the valvemechanism allows motive fluid to be admitted to the piston-chamber for asufliciently-long period of time to properly actuate the piston, andalso it occurs without jarring by reason of the fact that both of thevalves are cushioned against shock at the ends of their strokes.

lVith reference to the construction of said piston-valve D andsupplemental valve E and of the cylinder F, providing the piston-valvechamber D, the same can be conveniently constructed as follows: Thepiston-valve D can be constructed of a hollow exterior shell d, a hollowinterior shell (1, fitted tightly within the exterior shell (Z andhaving a bore adapted to form the chamber for the supplemental valve,and a couple of screw-threaded plugs or end pieces d (1 adapted to fitinto the ends of the bore of the interior shell d. The exterior shell dcan have the requisite recesses 25 26 37, 820., formed in its exteriorsurface, and can also have additional recesses formed therein for theaccommodation of packing-washers or the like, which are particularlywell adapted to provide the cylindrical heads 27 27, (he. The innercylindrical shell cl can have the longitudinal ports 30 and 30 formed inits exterior surface before it is inserted within the exterior shell d,after which insertion the radial ports 28 29, &c., can be bored in bothshells. Such construction is inexpensively and easily made and isparticularly advantageous, in that it provides for the convenientformation of the longitudinal ports 30 and 30 and the end and sideopenings 31, 32, 31, and 32 thereof. The supplemental valve E can beconstructed in suitable cylindrical form and can be provided with therequisite recesses and cylindrical heads, which latter can be providedwith suitable packing-rings for making them tight against the leakage ofmotive fluid. The piston-valve cylinder F can be suitably constructedwith a hollow extension F, adapted to provide the inlet-chamber 21, andcan be provided with removable screw-threaded ends f f, whereby thepiston-valve can be readily removed and replaced. Each pair ofsupply-ports 23 24 and 23 24 could be replaced by a singleport ofsubstantially the width of the space between the farthest-removed wallsof each pair; but the arrangement shown is preferred, as thepacking-washers forming the heads 39 39 cannot enter either of the smallports, whereas they might enter a large port and be injured or torn fromtheir position. Such construction of valve mechanism can be easilyconstructed and can be operated economically and with little attendanceand repair or replacement of ports. Also the difficulty of forming portsin the valve-seat and the inconvenience of having ports which areinaccessible by reason of their being located in the valve-seat areavoided.

In the valve mechanism illustrated in Figs. 13 to 15, inclusive, of thedrawings, the cylinderF, providing the piston-valve chamber D, isarranged intermediate of the pistonchamberAand the supplemental-val vechamber E, and the latter is provided by a separate cylinder G andcommunicates primarily with the inlet-port 22 formed in the front sideof the cylinder G. chamber D and the piston-valve chamber are connectedby a couple of ports 23 and 23, so as to supply the latter with motivefluid for the piston-chamber. In order to distribute such motive fluidto the piston-chamber, the piston-valve D is constructed in am annersubstantially similar to the piston-valve illustrated in the precedingarrangement- -that is to say, said piston-valve is provided withcircumferential recesses 25 and 25, formed by cylindrical heads 39 and27 and 39 and 27, respectively, which said recesses are adapted to allowmotive fluid to pass from the upper supply-port 23 into the upperinlet-port 17 when the piston-valve is below a predetermined point inits stroke and to pass from the lower supply-port 23 into the lowerinlet-port 17 when the piston-valve is above a predetermined point inits stroke. Also said piston-valveis provided with an intermediatecircumferential recess 26,formed by theheads 27 and 27, which saidrecess 26 is adapted to allow the lower end of the piston-chamber toexhaust into the main exhaust-port 19 when said valve is below the lowerpredetermined point and to allow the upper end of the piston-chamber toexhaust into said main exhaust-port 19 when the valve is above the upperpredetermined point.

The arrangement for reciprocating the piston-valve comprises ports 30and 30, formed longitudinally in the wall H, separating thevalve-chambers from one another and provided, respectively, with outerend openings opening into the ends of the piston-valve chamber and withinner end openings 32 and 32, respectively, opening into said chambernear its longitudinal middle, and also with intermediate side openings31 and 31, respectively, opening into the supplementalvalve chamber E.Bysuch arrangement the upper end of the piston-valve chamber can receivemotive fluid from the supplementalvalve chamber by way of the sideopening 31 and the outer end opening of the port 30 and the intermediateportion of said port 30, so as to drive the piston-valve downward,during which downward movement thelower end of the piston-valve chambercan exhaust into the main exhaust-port 19 by way of the port 30 and itsend openings and the intermediate piston-valve recess 26, and also thelower end of the piston-valve chamber can receive The supplemental-valvemotive fluid by way of the outer end opening of the port 30, the sideopening 31 thereof, and the intermediate portion of said port, so as todrive the piston-valve upward, during which upward movement the upperend of the piston-valve chamber can exhaust into the main exhaust-port19 by way of the port 30 and its end openings and said intermediaterecess 26. To such end the supplemental valve E is constructed with acircumferential recess 34 and a couple of end cylindrical heads 36 and36 forming such recess 34, whereby when said valve is at the upper endof its stroke its recess 34 is in communication with the side opening 31of the port 30, and its lower head 36 closes the side ope-ning 31 of theport 30, and also when said valve is at the lower end of its stroke itsrecess 34 is in communication with said side opening 31, and its upperhead 36 closes said side opening 31. The descent of the supplementalvalve therefore causes the rise of the piston-valve, and, conversely,its rise causes the descent of said piston-valve. The arrangement forreciprocating the supplemental valve to such end comprises a conple ofports 38 and 38, extending longitudinally in said separating-wall H andhaving, respectively, outer end openings opening into the ends of thesupplemental-valve chamber and inner end openings 38 and 38,respectively, opening into the piston-valve chamber on opposite sides ofits longitudinal middle. By such arrangement when the piston-valve D hasrisen sufficiently to place its lower recess 25 into communication withthe inner end opening 38 of the port 38 motive fluid passes from saidrecess into the lower end of supplemental-valve chamber and drives thesupplemental valve upward, during which upward movement of said valvethe upper end of .its chamber exhausts, by way of the port 38, into theintermediate piston-valve recess 26, and thence into the mainexhaust-port 19, and also when the piston-valve has descendedsufficiently to place its upper recess 25 into communication with theend opening 38 of the port 38 motive fluid passes from said recess intothe upper end of the supplementalvalve chamber and drives saidsupplemental valve downward, during which downward movement of saidvalve the lower end of its chamber exhausts, by way of the port 38, intosaid recess 26 and thence into said exhaust-port 19. The inner endopenings 38 and 38 of said ports 38 and 38 could be so situated as toadmit motive fluid to the supplemental-valve chamber at any desired timeafter the same has been admitted to the piston-chamber; but as apreferred arrangement said end openings 38 and 38 are so situated as toadmit motive fluid to the supplementalvalve chamber only at a time whenthe piston-valve arrives at one or the other of the ends of its stroke.The operation of this latter valve arrangement is similar to that of thepreceding arrangementthat is to say,

chamber and the supplemental valve descends, which descent of thesupplemental valve operates to admit motive fluid to the.

lower end of the piston-valve chamber and causes the piston-valve torise, and when the piston-valve arrives at the upper end of its stroke,as shown in Fig. 13, motive fluid is admitted to the lower end of thesupplementalvalve chamber and the supplemental valve rises, which riseof the supplemental valve operates to admit motive fluid to the upperend of the piston-valve chamber and causes the piston-valve to descend,and so on, as before. With reference to the construction of this lattervalve arrangement the valves D and E are conveniently and inexpensivelyconstructed of properly-recessed cylinders, while the cylinders F and G,providing the valve-chambers D and E, respectively, are suitablyconstructed in cylindrical form and are desirably providedwithdetachable ends f f and g g, respectively, whereby said valves canbe easily removed and replaced. The wall H, separating thevalve-chambers D and E from one another, is conveniently provided by theadjacent sides of the cylinders F and G, which said sides areaccordingly provided in any suitable manner with the requisite ports. Asa preferred arrangement the ports 38 and 38 are conveniently formed inthe bottom of the cylinder G, Fig. 15, before the same is attached inposition to the cylinder F, and in order to avoid interference with theports 23 and 23 and the side openings 31 and '31 of the ports 30 and 30said ports 38 and 38 are constructed with loop portions 38 and 38,respectively, which severally encircle one of said ports 23 and 23 andone of said side openings 31 and 31; also, the longitudinal ports 30 and30 are constructed with loop portions 30 and 30, respectively, whichseverally encircle one of said ports 23 and 23 and one of the inner endopenings 38 and 38 of the ports 38 and 38.

With reference to the common features of the two valve arrangements itwill be observed that in both of the same the sets of ports leading tothe piston-chamber and to the supplemental-valve chamber, respectively,and controlled by the piston-valve for distributing motive fluid to saidchamber have separate terminal openings in the piston-valve chamber,which said openings are so situated as to admit motive fluid to thepiston-chamber before and for a greater length of time than the same isadmitted to the supplemental-valve chamber, and also that as a preferredarrangement motive fluid is admitted to the supplemental valve chamberonly at a time when the piston-valve arrives at one or the other of theends of its str'oke.

In order to prevent an undesirable shock on the part of the pistonarrangement upon the arrival of the same at the ends of its stroke, theinlet-ports 17 and 17 are provided with side openings 17 and 17,respectively, which said side openings are situated at short distancesfrom the ends of the piston-chamber and are adapted to be closed by thepiston-heads B and B, respectively, when said piston-heads approach oneor the other of the ends of their stroke. Said ports 17 and 17 are alsoprovided at their ends with springcontrolled check-valves 45 and 45,respectively, which said check-valves are arranged to open outwardlyfrom the end of said ports 17 and 17, so as to allow the passage of motive fluid from the latter into the piston-chamber, but to prevent itspassage from the piston-cham her back into said ports. By sucharrangement the escape of motive fluid exhausting from the ends of thepiston-chamber as the piston-heads approach one or the other of the endsof their strokes is prevented and the motive fluid so confined againstescapement is compressed by the further progression of the pistonarrangement, so as to form an elastic abutment acting in opposition tosuch further progression and providing at the same time a high initialpressure for the return stroke of said piston arrangement.

\Vith reference to the construction of the cylinder A, which providesthe piston-chamber A, said cylinder A is constructed with a rearextension A for attachment to a suitable support and is desirablyprovided with a detachable upper end piece 46 and a detachablestuffing-box t7 for the piston-rod at its lower end. The stufling-box 47could be constructed in any suitable manner; but as a matter of furtherimprovement it is constructed of a single piece, whereby it is alwaystight against leakage of the motive fluid and also whereby is avoidedthe employment of nuts and bolts, which would be necessary for securingits parts together should it be constructed of two or more pieces. Thesaid stuffing-box 47 is provided with a suitable bore for thepacking-glands, which said bore is desirably of greater diameter thanthe diameter of the piston-heads B and B, whereby when it is desired toremove said piston-heads from the piston-chamber for any purpose theycan be withdrawn through the stuffing-box without detaching the latter.Said stuffing-box incloses a couple of packing-glands 48 and 49, whichoccupy the upper and lower ends, respectively, of its bore, and itincloses also a suitable bundle of packing confined between said glands.The upper packing-gland 48 is capable of easy insertion in and removalfrom the upper end of the stuffing-box 47 when the said stuffing-box isdetached from the pistoncylinder, and when so inserted within said upperend fits against the lower end of the piston-cylinder, it being observedthat the diameter of the packing-gland 1-8, being substantially the sameas that of the bore of the stuffing-box 47, is greater than that of thebore of the pistoncylinder, and that said gland therefore is preventedfrom entering the bore of the piston-cylinder by reason of its greaterdiameter, but abuts against the lower end of said cylinder. The lowerpacking-gland 40 screws into and out of said stuffing-box 4:7 for theadjustment of the packing confined between the two glands by way ofcorresponding screw-threads with which it and the lower end of thepacking-box are provided. Said packing-glands 48 and 49 are eachdesirably constructed of two longitudinal halves, so as to permit oftheir being easily removed from and replaced upon the piston-rod withoutnecessitating the detachment of either the piston-heads or the drillattachment.

The end piece 46 of the piston-cylinder and the stuffing-box A7 for thepiston-rod could be detachably secured to said cylinder in any preferredmanner. As a matter of further improvement, however, both the end pieceand the stuffing-box are secured to the cylinder by a number of longrods 50, which extend the entire length of said cylinder and passthrough suitable flanges formed at the ends of the cylinder and of thestuffing-box, respectively, and which are held in place by means ofsuitable nuts fitted upon their screw-threaded ends. By such arrangementthe employment of an undesirably large number of bolts and nuts forsecuring the end piece and the stuffing-box to the ends of thepiston-cylinder is dispensed with, and also the said end piece andstufiing-box can be tightened up by the adjustment of a single set ofnuts.

\Vhat I claim is 1. The combination with a piston and a portedpiston-chambcr therefor, of a fluidactuated reciprocating piston-valvefor distributing motive fluid to the piston-chamber, and afluid-actuated reciprocating supplemental valve, said valves beingarranged to distribute motive fiuid for reciprocating one another, andthe piston-valve being arranged to admit motive fluid to thesupplementalvalve chamber foractuating the supplemental valve at a timeafter it has admitted the same to the piston-chamber for actuating thepiston, as set forth.

2. The combination, with a piston and a ported piston-chamber therefor,of a fluidaetuated reciprocating valve fordistributing motive fluid tothe piston -chamber, and a fluid actuated reciprocating supplementalvalve,said valves being arranged to distribute motive fluid forreciprocating one another, and the piston-valve being arranged to admitmotive fluid for actuating the supplemental valve at a time after it hasadmitted the same to the piston-chamber for actuating the piston andwhen it has arrived at one or the other of the ends of its stroke, asset forth.

3. The combination with a piston and a ported piston-chamber therefor,of a fluidactuated reciprocating piston-valve for distributing motivefluid to the piston-chamber, and a fluid-actuated reciprocatingsupplemental valve, said valves being arranged to distribute motivefluid for reciprocating one another, and the piston-valve being arrangedto admit motive fluid for actuating the piston for a longer period oftime than for actuating the supplemental valve, as set forth.

4. An impact-tool having a reciprocating piston operated by means of afluid-actuated reciprocating valve which distributes motive fluid to thepiston-chamber and a fluid-actuated reciprocating supplemental valvearranged for distributing motive fluid for reciprocating thepiston-valve, and reciprocated by motive fluid distributed to it by thepiston-valve; and constructed with ports extending from both thepiston-chamber and the supplemental-valve chamber to the piston valvechamber, and having separate terminal openings in the latter, as setforth.

5. The combination, with the piston and ported piston-chamber therefor,of a fluidactuated reciprocating piston-valve for dis tributing motivefluid to the piston-chamber and a fluid-actuated reciprocatingsupplemental valve inclosed in a chamber formed interiorly in saidpiston-valve, said valves being arranged for distributing motive fluidfor reciprocating one another, as set forth.

6. The combination, with the piston and ported piston-chamber therefor,of a fluidactuated reciprocating piston-valve for distributing motivefluid to the piston-chamber, and a fluid-actuated reciprocatingsupplemental valve inclosed in a chamber formed interiorly in saidpiston-valve, said valves being arranged for distributing motive fluidfor reciprocating one another, and the pistonvalve being arranged toadmit motive fluid to the piston-chamber at a time before it admits thesame to the supplemental valve chamber, as set forth.

7. The combination with the piston and ported cylinder therefor, of afluid-actuated reciprocating piston-valve for distributing motive fluidto the piston-chamber, and a fluid actuated reciprocating supplementalvalve confined in acha'mber formed-interiorly in the piston-valve, saidpiston-valve being provided with ports arranged to admit motive fluid toone or theother of its ends when the supplemental valve is at acorresponding end of its valve-chamber, and also with inwardlyextendingports adapted to conduct motive fluid to one or the other of the ends ofsaid interior chamber, and being inclosed in a valve-chamber havingports arranged to communicate with one or the other of saidinwardly-extending ports according as the piston-valve is at one or theother of the ends of its stroke so as to admit motive fluid t0 the endof the supplemental-valve chamber at which the supplemental valve issituated, substantially as set forth.

8. The combination with the fluid-actuated reciprocating supplementalvalve, of the reciprocating piston-valve constructed with an interiorchamber in which said supplemental valve is confined, and provided withexhaust- .ports having openings adapted to be closed by the supplementalvalve at a time before said supplemental valve has reached the ends ofits strokes whereby the same is cushioned against shock as set forth.

9. The combination with the reciprocating supplemental valve,of thereciprocating fluidactuated piston-valve constructed with an interiorvalve-chamber in which said supplemental valve is confined, andprovidedwith inlet-ports adapted to conduct motive fluid from thesupplemental-valve chamber into its chamber to one or the other of itsends,

according as the supplemental valve is at one or the other of the endsof its stroke and provided with additional openings arranged to beuncovered by said supplemental valve before the same has reached theends of its stroke, whereby thepiston-valve is cushioned against shock,substantially as set forth.

10. In an impact-tool, the combination of the piston comprising a coupleof separated piston-heads, and a connecting-rod connecting the same; andan intermittently-twisting device arranged within the piston-chamber andengaging the connecting-rod intermediate of the piston-heads,substantially as and for the purpose set forth.

11. In an impact-tool, the combination of the piston comprising a coupleof separated piston-heads and a spirally-grooved connecting-rod attachedto the same; andan intermittently-twisting device engaging theconnecting-rod intermediate of the piston-heads and comprising a .fixedcollar provided with engaging portions and fitted loosely over theconnecting-rod, a loose collar provided with corresponding engagingportions and also with inwardly-projecting tongues adapted to engage thespiral grooves of the connectingrod, and having a friction connectionwith the latter, and a stop for limiting the movement of the loosecollar longitudinally of the piston-chamber, substantially as set forth.

12. In an impact-tool, the combination with a couple of separatedpiston-heads and aspirally-grooved connecting-rod attached thereto, of afixed collar provided with engaging portions and fitted loosely over theconnecting-rod; a loose collar provided with corresponding engagingportions and also with inwardly-projecting tongues adapted to engage thespiral grooves of the connecting-rod; a friction-ring inclosing theconnecting-rod and confined in an annular chamber in the loose collar;and a sleeve in which said collars are inclosed, said sleeve beingfitted within the piston-chamber and being constructed with aninwardly-projecting flange adapted to form a stop to limit the movementof the loosecollar longitudinally of the piston-chamber, substantiallyas described.

13. In an impact-tool, the combination of a spirally-groovedreciprocating rod connected with the implement for reciprocating thesame; and an intermittently-twisting device comprising'afixed toothedcollarfitted loosely tion longitudinally of the reciprocating rod, overthe reciprocating rod, a corresponding as set forth.

toothed loose collar havin afriction connection with said rod andprovided with in- RHODES 5 wardly-projecting teeth for engaging the spi-Witnesses:

ral groove thereof, andastop adapted tolimit A. F. DURAND,

the movement of said loose collar in a direc- A. MILLER BELFIELD.

